Method of fabricating light-emitting apparatus with improved light extraction efficiency and light-emitting apparatus fabricated using the method

ABSTRACT

Provided are a method of fabricating a light-emitting apparatus with improved light extraction efficiency and a light-emitting apparatus fabricated using the method. The method includes: preparing a monocrystalline substrate; forming an intermediate structure on the substrate, the intermediate structure comprising a light-emitting structure which comprises a first conductive pattern of a first conductivity type, a light-emitting pattern, and a second conductive pattern of a second conductivity type stacked sequentially, a first electrode which is electrically connected to the first conductive pattern, and a second electrode which is electrically connected to the second conductive pattern; forming a polycrystalline region, which extends in a horizontal direction, by irradiating a laser beam to the substrate in the horizontal direction such that the laser beam is focused on a beam-focusing point within the substrate; and cutting the substrate in the horizontal direction along the polycrystalline region.

This application claims priority from Korean Patent Application No.10-2008-0111060 filed on Nov. 10, 2008 in the Korean IntellectualProperty Office, the entire contents of which are incorporated herein byreference.

BACKGROUND

1. Field of the Invention

The present inventive concept relates to a method of fabricating alight-emitting apparatus and a light-emitting apparatus fabricated usingthe method.

2. Description of the Related Art

Light-emitting apparatuses such as light-emitting diodes (LEDs) emitlight when electrons combine with holes. Light-emitting apparatusesconsume low power, have a long life, can be installed in a limitedspace, and are resistant to vibrations.

A major challenge in the development of light-emitting apparatuses is toimprove light extraction efficiency. Light extraction efficiency is theproportion of light, which exits a light-emitting apparatus into, forexample, air or transparent resin that surrounds the light-emittingapparatus), in light generated within the light-emitting apparatus. Alight-emitting apparatus may have an optical refractive index ofapproximately 2.2 to 3.8, air may have an optical refractive index of 1,and transparent resin may have an optical refractive index ofapproximately 1.5.

For example, when a light-emitting apparatus has an optical refractiveindex of 3.4, a portion of light generated within the light-emittingapparatus may exitexit the light-emitting apparatus into the air at acritical angle of approximately 17 degrees and into transparent resin ata critical angle of approximately 26 degrees.

In this case, the light extraction efficiency of the light-emittingapparatus is approximately 2.2% when a portion of light generated withinthe light-emitting apparatus exits the light-emitting apparatus into theair, and the light extraction efficiency of the light-emitting apparatusis approximately 4% when the portion of the light generated within thelight-emitting apparatus exits the light-emitting apparatus intotransparent resin. The other portion of the light is reflected by asurface of the light-emitting apparatus and trapped in thelight-emitting apparatus.

SUMMARY

Aspects of the present inventive concept provide a method of fabricatinga light-emitting apparatus with improved light extraction efficiency.

Aspects of the present inventive concept also provide a light-emittingapparatus fabricated using the above method.

According to an aspect of the present inventive concept, there isprovided a method of fabricating a light-emitting apparatus. The methodincludes: preparing a monocrystalline substrate; forming an intermediatestructure on the substrate, the intermediate structure comprising alight-emitting structure which comprises a first conductive pattern of afirst conductivity type, a light-emitting pattern, and a secondconductive pattern of a second conductivity type stacked sequentially, afirst electrode which is electrically connected to the first conductivepattern, and a second electrode which is electrically connected to thesecond conductive pattern; forming a polycrystalline region, whichextends in a horizontal direction, by irradiating a laser beam to thesubstrate in the horizontal direction such that the laser beam isfocused on a beam-focusing point within the substrate; and cutting thesubstrate in the horizontal direction along the polycrystalline region.

In one embodiment, the method further comprises bonding the substratehaving the intermediate structure formed thereon to a support substratebetween the forming of the intermediate structure and the forming of thepolycrystalline region.

In one embodiment, the first conductive pattern has a protruding regionsince the first conductive pattern is wider than the second conductivepattern, the first electrode is formed on the protruding region of thefirst conductive pattern, the second electrode is formed on the secondconductive pattern, and the substrate having the intermediate structureformed thereon is bonded to the support substrate such that the firstand second electrodes face the support substrate.

In one embodiment, sidewalls of the light-emitting structure areinclined, and the second electrode is formed on a top surface and thesidewalls of the light-emitting structure.

In one embodiment, when the substrate is cut in the horizontaldirection, the substrate is divided into a first substrate and a secondsubstrate from the polycrystalline region, wherein the intermediatestructure is formed on a first surface of one of the first and secondsubstrates, and a cut pattern region is formed on a second surface ofone of the first and second substrates, wherein at least part of the cutpattern region is polycrystalline. In one embodiment, the method furthercomprises forming a reflective metal film on the second surface of oneof the first and second substrates on which the cut pattern region isformed.

In one embodiment, the laser beam has a wavelength of more than 1000 nm.

According to another aspect of the present inventive concept, there isprovided a method of fabricating a light-emitting apparatus. The methodincludes: preparing a monocrystalline substrate; forming an intermediatestructure on the substrate, the intermediate structure comprising alight-emitting structure which comprises a first conductive pattern of afirst conductivity type, a light-emitting pattern, and a secondconductive pattern of a second conductivity type stacked sequentially, afirst electrode which is electrically connected to the first conductivepattern, and a second electrode which is electrically connected to thesecond conductive pattern; forming a region, whose material quality isdifferent from that of the other regions of the substrate and whichextends in a horizontal direction, by irradiating a laser beam to thesubstrate in the horizontal direction such that the laser beam isfocused on a beam-focusing point within the substrate; and cutting thesubstrate in the horizontal direction along the region.

According to another aspect of the present inventive concept, there isprovided a light-emitting apparatus including: a substrate having afirst surface and a second surface; a light-emitting structure includinga first conductive pattern of a first conductivity type, alight-emitting pattern, and a second conductive pattern of a secondconductivity type which are stacked sequentially on the first surface ofthe substrate; a first electrode electrically connected to the firstconductive pattern; and a second electrode electrically connected to thesecond conductive pattern, wherein a cut pattern region is formed on thesecond surface of the substrate, the substrate is monocrystalline, andat least part of the cut pattern region is polycrystalline.

In one embodiment, the apparatus further comprises a support substrateattached to the substrate, wherein the first and second electrodes facethe support substrate.

Aspects of the present inventive concept are not restricted to those setforth herein. The above and other aspects of the present inventiveconcept will become more apparent to one of ordinary skill in the art towhich the present inventive concept pertains by referencing the detaileddescription of the present inventive concept given below.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of the inventive conceptwill be apparent from the more particular description of preferredaspects of the inventive concept, as illustrated in the accompanyingdrawings in which like reference characters refer to the same partsthroughout the different views. The drawings are not necessarily toscale, emphasis instead being placed upon illustrating the principles ofthe inventive concept. In the drawings, the thickness of layers andregions are exaggerated for clarity.

FIGS. 1 through 5 are views showing intermediate processes included in amethod of fabricating a light-emitting device according to a firstexemplary embodiment of the present inventive concept.

FIG. 6 is a view showing the operation of the light-emitting deviceaccording to the first exemplary embodiment of the present inventiveconcept.

FIGS. 7A and 7B are cross-sectional views of a light-emitting deviceaccording to a second exemplary embodiment of the present inventiveconcept.

FIGS. 8A and 8B are cross-sectional views of a light-emitting deviceaccording to a third exemplary embodiment of the present inventiveconcept.

FIG. 9 is a view showing the operation of the light-emitting deviceaccording to the third exemplary embodiment of the present inventiveconcept.

FIG. 10 is a view showing a light-emitting apparatus according to afourth exemplary embodiment of the present inventive concept.

FIG. 11 is a view showing a light-emitting apparatus according to afifth exemplary embodiment of the present inventive concept.

FIG. 12 is a view showing a light-emitting apparatus according to asixth exemplary embodiment of the present inventive concept.

FIG. 13 is a view showing a light-emitting apparatus according to aseventh exemplary embodiment of the present inventive concept.

FIG. 14 is a view showing a light-emitting apparatus according to aneighth exemplary embodiment of the present inventive concept.

FIG. 15 is a view showing a light-emitting apparatus according to aninth exemplary embodiment of the present inventive concept.

FIGS. 16 through 18 are views showing a light-emitting apparatusaccording to a tenth exemplary embodiment of the present inventiveconcept.

FIG. 19 is a view showing a light-emitting apparatus according to aneleventh exemplary embodiment of the present inventive concept.

FIGS. 20 through 23 are views showing light-emitting apparatusesaccording to twelfth through fifteenth exemplary embodiments of thepresent inventive concept.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Advantages and features of the present inventive concept and methods ofaccomplishing the same may be understood more readily by reference tothe following detailed description of exemplary embodiments and theaccompanying drawings. The present inventive concept may, however, beembodied in many different forms and should not be construed as beinglimited to the embodiments set forth herein. Rather, these embodimentsare provided so that this description will be thorough and complete andwill fully convey the concept of the inventive concept to those skilledin the art, and the present inventive concept will only be defined bythe appended claims. In the drawings, sizes and relative sizes of layersand regions may be exaggerated for clarity.

It will be understood that when an element or layer is referred to asbeing “on” another element or layer, the element or layer can bedirectly on another element or layer or intervening elements or layers.In contrast, when an element is referred to as being “directly on”another element or layer, there are no intervening elements or layerspresent. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items.

Spatially relative terms, such as “below”, “beneath”, “lower”, “above”,“upper”, and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. Like reference numerals refer tolike elements throughout the specification.

Embodiments of the inventive concept are described herein with referenceto plan and cross-section illustrations that are schematic illustrationsof idealized embodiments of the inventive concept. As such, variationsfrom the shapes of the illustrations as a result, for example, ofmanufacturing techniques and/or tolerances, are to be expected. Thus,embodiments of the inventive concept should not be construed as limitedto the particular shapes of regions illustrated herein but are toinclude deviations in shapes that result, for example, frommanufacturing. The regions illustrated in the figures are schematic innature and their shapes are not intended to illustrate the actual shapeof a region of a device and are not intended to limit the scope of theinventive concept.

FIGS. 1 through 5 are views showing intermediate processes included in amethod of fabricating a light-emitting device 1 according to a firstexemplary embodiment of the present inventive concept. In particular,FIG. 5 is a cross-sectional view showing a cut pattern region 104 of thelight-emitting device 1 according to the first exemplary embodiment ofthe present inventive concept. FIG. 6 is a view showing the operation ofthe light-emitting device 1 according to the first exemplary embodimentof the present inventive concept.

Referring to FIG. 1, intermediate structures are formed on a substrate100 a, and the substrate 100 a is separated into individual chips(intermediate structures).

Specifically, an intermediate structure shown in FIG. 1 includes thesubstrate 100 a, a light-emitting structure 110 which includes a firstconductive pattern 112, a light-emitting pattern 114, and a secondconductive pattern 116 stacked sequentially, a first electrode 140 whichis electrically connected to the first conductive pattern 112, and asecond electrode 150 which is electrically connected to the secondconductive pattern 116.

The substrate 100 a may be monocrystalline. In addition, the substrate100 a may be made of a material from which the first conductive pattern112, the light-emitting pattern 114, and the second conductive pattern116 can grow. For example, the substrate 100 a may be an insulatingsubstrate made of sapphire (Al₂O₃) or zinc oxide (ZnO) or may be aconductive substrate made of silicon (Si), silicon carbide (SiC), orgallium nitride (GaN).

The first conductive pattern 112, the light-emitting pattern 114, andthe second conductive pattern 116 of the light-emitting structure 110may include In_(x)Al_(y)Ga_((1-x-y))N (0≦x≦1, 0≦y≦1) (i.e., variousmaterials containing GaN). For example, the first conductive pattern112, the light-emitting pattern 114, and the second conductive pattern116 may include AlGaN or InGaN.

The first conductive pattern 112 may be of a first conductivity type(e.g., an n type), and the second conductive pattern 116 may be of asecond conductivity type (e.g., a p type). Conversely, the firstconductive pattern 112 may be of the second conductivity type (the ptype), and the second conductive pattern 116 may be of the firstconductivity type (the n type), depending on the design of thelight-emitting device.

The light-emitting pattern 114 is a region where light is generated whencarriers (e.g., electrons) of the first conductive pattern 112 combinewith carriers (e.g., holes) of the second conductive pattern 116.Although not specifically shown in the drawing, the light-emittingpattern 114 may include a well layer and a barrier layer. Since the welllayer has a smaller band gap than the barrier layer, carriers (electronsand holes) gather in the well layer and combine together. Thelight-emitting pattern 114 may have a single quantum well (SQW)structure or a multiple quantum well (MQW) structure, depending on thenumber of well layers included in the light-emitting pattern 114. TheSQW structure includes only one well layer while the MQW structureincludes a plurality of well layers. In order to control light-emittingproperties, at least one of the well layer and the barrier layer may bedoped with at least one of boron (B), phosphorous (P), silicon (Si),magnesium (Mg), zinc (Zn), selenium (Se), and aluminum (Al).

The light-emitting structure 110 may have inclined sidewalls. Theinclined sidewalls of the light-emitting structure 110 may allow lightgenerated within the light-emitting pattern 114 to be reflected by thesecond electrode 150, which is formed on a top surface and the sidewallsof the light-emitting structure 110, and then to easily escape from thelight-emitting structure 110 without being trapped within thelight-emitting structure 110. That is, the light extraction efficiencyof the light-emitting device 1 can be improved, which will be describedin detail below with reference to FIG. 6.

As shown in FIG. 1, the first conductive pattern 112 may be wider thanthe second conductive pattern 116 and the light-emitting pattern 114.Thus, a portion of the first conductive pattern 112 may protrude in alateral direction (that is, the first conductive pattern 112 mayprotrude further than the second conductive pattern 116 or thelight-emitting pattern 114).

An insulating layer 120 is conformally formed along the profile of thelight-emitting structure 110 and patterned to expose a portion of thefirst conductive pattern 112 and a portion of the second conductivepattern 116. The insulating layer 120 may be a silicon oxide film, asilicon nitride film, an aluminum oxide film, or an aluminum nitridefilm.

A first ohmic layer 131 and the first electrode 140 may be formed on theportion of the first conductive pattern 112 exposed by the insulatinglayer 120, and a second ohmic layer 132 and the second electrode 150 maybe formed on the portion of the second conductive pattern 116 exposed bythe insulating layer 120. That is, the first electrode 140 may be formedon a protruding region of the first conductive pattern 112, and thesecond electrode 150 may be formed on the top surface and sidewalls ofthe light-emitting structure 110.

Each of the first and second ohmic layers 131 and 132 may include atleast one of indium tin oxide (ITO), zinc (Zn), zinc oxide (ZnO), silver(Ag), tin (Ti), aluminum (Al), aurum (Au), nickel (Ni), indium oxide(In₂O₃), tin oxide (SnO₂), copper (Cu), tungsten (W), and platinum (Pt).In addition, each of the first and second electrodes 140 and 150 mayinclude at least one of ITO, Cu, Ni, chrome (Cr), Au, titanium (Ti), Pt,Al, vanadium (V), W, molybdenum (Mo), and Ag.

Although not shown in the drawing, a buffer layer may be formed betweenthe substrate 100 a and the first conductive pattern 112. The bufferlayer may be used as a seed layer for forming the first conductivepattern 112, the light-emitting pattern 114, and the second conductivepattern 116. In addition, the buffer layer may be used to preventlattice mismatch between the substrate 100 a and the light-emittingstructure 110. Thus, the buffer layer improves the membranous propertiesof the light-emitting structure 110. The buffer layer may be made of anymaterial that enables the buffer layer to serve as a seed layer. Forexample, the buffer layer may be made of In_(x)Al_(y)Ga_((1-x-y))N(0≦x≦1, 0≦y≦1) or Si_(x)C_(y)N_((1-x-y)) (0≦x≦1, 0≦y≦1).

Referring to FIG. 2, the substrate 100 a, on which the intermediatestructure shown in FIG. 1 is formed, is bonded to a support substrate160. Specifically, any substrate can be used as the support substrate160 as long as it can bond the intermediate structure thereto. Thesupport substrate 160 may be, for example, a submount, a circuit board,or a package. A first conductive region 161 and a second conductiveregion 162 may be formed on the support substrate 160 and may beelectrically insulated from each other. The first and second conductiveregions 161 and 162 may be disposed on a surface of the supportsubstrate 160.

The substrate 100 a and the support substrate 160 are bonded togethersuch that the first and second electrodes 140 and 150 of thelight-emitting device 1 face the support substrate 160. That is, thesubstrate 100 a and the support substrate 160 may be bonded together ina flip-chip manner. Specifically, the first electrode 140 of thelight-emitting device 1 may be connected to the first conductive region161 of the support substrate 160 by a conductive solder 171, and thesecond electrode 150 of the light-emitting device 1 may be connected tothe second conductive region 162 of the support substrate 160 by aconductive solder 172. Although not shown in the drawing, the secondelectrode 150 and the second conductive region 162 may also be directlyattached and connected to each other without requiring the conductivesolder 172.

Referring to FIGS. 3 and 4, a polycrystalline region 102 is formed in apredetermined region within the substrate 100 a.

Specifically, a permeable nanosecond pulse laser beam may be irradiatedto the substrate 100 a in a horizontal direction such that it is focusedon a beam-focusing point 103 within the substrate 100 a. As a result,the polycrystalline region 102, which extends in the horizontaldirection, may be formed within the substrate 100 a. That is, when thesubstrate 100 a is scanned with a laser beam, the polycrystalline region102 may be formed within the substrate 100 a. This is because the laserbeam converts monocrystals of the substrate 100 a into polycrystals. Thepolycrystalline region 102 formed as described above may divide thesubstrate 100 a into a first substrate 100 b and a second substrate 100c.

The horizontal direction may denote a direction in which the substrate100 a extends or a direction substantially parallel to a first or secondsurface of the substrate 100 a.

Referring to FIG. 4, a laser beam may be concentrated by a focusing lens108 to form the beam-focusing point 103 within the substrate 100 a.

Here, the laser beam may have a wavelength that is not absorbed by asurface of the substrate 100 a. A wavelength range of the laser beam,which can pass through the substrate 100 a without being absorbed by thesurface of the substrate 100 a, may vary according to the material orthickness of the substrate 100 a. In the case of a silicon substrate,the laser beam may have a wavelength range of more than 1000 nm, forexample, a wavelength of 1065 nm. A laser beam having a wavelength rangeof less than 1000 nm cannot pass through the silicon substrate and thuscannot be used.

The beam-focusing point 103 may be formed at a specified depth from thesurface of the substrate 100 a. The specified depth at which thebeam-focusing point 103 is formed may vary according to a thickness ofthe first substrate 100 b which will remain after the substrate 100 a iscut.

Referring to FIG. 5, the substrate 100 a is cut in the horizontaldirection along the polycrystalline region 102 to complete thelight-emitting device 1.

Specifically, stress (e.g., tensile stress) is applied to the substrate100 a having the polycrystalline region 102 formed therein, therebycutting the substrate 100 a in the horizontal direction along thepolycrystalline region 102. That is, since the second substrate 100 c isseparated from the first substrate 100 b, the thickness of the substrate100 a, which has the light-emitting structure 110 and the first andsecond electrodes 140 and 150 formed on the first surface thereof, canbe reduced.

In particular, when the substrate 100 a is cut in the horizontaldirection by using a laser beam, the cut pattern region 104 is formed ona second surface of the first substrate 100 b. The second surface isopposite to the first surface on which the light-emitting structure 110and the first and second electrodes 140 and 150 formed. As shown in thedrawing, the cut pattern region 104 has roughness. Due to the cutpattern region 104 having a predetermined roughness, light generatedwithin the light-emitting structure 110 can easily exitexit thesubstrate 100 a without being trapped in the substrate 100 a. Inaddition, since the first substrate 100 b, which remains after thesubstrate 100 a is cut, is thin, there is a low probability that thegenerated light will be trapped in the first substrate 100 b.

At least part of the cut pattern region 104 may include a region 105which includes polycrystals. For example, as shown in the drawing, aportion of the cut pattern region 104 may be the region 105 whichincludes polycrystals, and the other portion of the cut pattern region104 may be a region 106 which includes monocrystals. This is because thesubstrate 100 a is cut along the polycrystalline region 102 by applyingstress mainly to the polycrystalline region 102. That is, polycrystalsmay remain on the cut surface of the substrate 100 a.

Although not shown in the drawings, the substrate 100 a may also beseparated into individual chips after being cut in the horizontaldirection by using a laser beam. Then, the chips may be attached to thesupport substrate in a flip-chip manner.

The operation of the light-emitting device 1 according to the firstexemplary embodiment will now be described with reference to FIG. 6.

Referring to FIG. 6, when the first conductive pattern 112 is of the ntype and when the second conductive pattern 116 is of the p type, afirst bias BIAS(−) is applied to the first conductive pattern 112 viathe first conductive region 161, the conductive solder 171, the firstelectrode 140 and the first ohmic layer 131, and a second bias BIAS(+)is applied to the second conductive pattern 116 via the secondconductive region 162, the conductive solder 172, the second electrode150 and the second ohmic layer 132. Conversely, when the firstconductive pattern 112 is of the p type and when the second conductivepattern 116 is of the n type, the second bias BIAS(+) is applied to thefirst conductive pattern 112 via the first conductive region 161, theconductive solder 171, the first electrode 140 and the first ohmic layer131, and the first bias BIAS(−) is applied to the second conductivepattern 116 via the second conductive region 162, the conductive solder172, the second electrode 150 and the second ohmic layer 132.

When biases are applied as described above, the light-emitting structure110 is forward-biased. The forward bias causes the light-emittingpattern 114 to generate light L1 and L2. The light L1 may travel towardthe first substrate 100 b without being reflected and then exitexit thefirst substrate 100 b. However, the light L2 may be reflected by thesecond electrode 150 that surrounds the light-emitting structure 110.Then, the reflected light L2 may travel toward the first substrate 100 bto exitexit the first substrate 100 b.

In particular, the cut pattern region 104 having a predeterminedroughness is formed on the second surface of the substrate 100 a in thefirst exemplary embodiment. Thus, the light L1 and L2 can escape fromthe substrate 100 a without being trapped therein. In addition, sincethe thickness of the substrate 100 a is reduced using a laser beam, theprobability that the light L1 and L2 will be trapped in the substrate100 a can be reduced. Consequently, the light extraction efficiency ofthe light-emitting device 1 is improved.

In the first exemplary embodiment, a case where monocrystals areconverted into polycrystals using a laser beam has been described.However, the scope of the present inventive concept is not limited tothis case. For example, characteristics or material of a region of asubstrate may be changed using a laser beam, and the substrate may becut in the horizontal direction along the region with the changedcharacteristics or material quality.

FIGS. 7A and 7B are cross-sectional views of a light-emitting device 2according to a second exemplary embodiment of the present inventiveconcept.

Referring to FIGS. 7A and 7B, the light-emitting device 2 according tothe second exemplary embodiment is different from the light-emittingdevice 1 according to the first exemplary embodiment in that a secondelectrode 150 is formed only on a top surface of a light-emittingstructure 110. Sidewalls of the light-emitting structure 110 may not beinclined as shown in FIG. 7A or may be inclined as shown in FIG. 7B. Inthis case, light generated within the light-emitting structure 110 maytravel toward the substrate 100 b and then exitexit the substrate 100 b.In addition, the generated light may exit the light-emitting structure110 in a direction toward the sidewalls of the light-emitting structure110.

FIGS. 8A and 8B are cross-sectional views of a light-emitting device 3according to a third exemplary embodiment of the present inventiveconcept. FIG. 9 is a view showing the operation of the light-emittingdevice 3 according to the third exemplary embodiment of the presentinventive concept. A support substrate 160 shown in FIGS. 8A through 9may be, for example, a circuit board or a package.

In the light-emitting device 1 according to the first exemplaryembodiment shown in FIG. 5, the first substrate 100 b, on which theintermediate structure is formed, is attached to the support substrate160 in a flip-chip manner. In contrast, in the light-emitting device 3according to the third exemplary embodiment shown in FIGS. 8A and 8B, afirst substrate 100 b, on which an intermediate structure is formed, isattached to the support substrate 160 in a lateral chip manner. That is,while the first and second electrodes 140 and 150 face the supportsubstrate 160 in the light-emitting device 1 according to the firstexemplary embodiment, they do not face the support substrate 160 in thelight-emitting device 3 according to the third exemplary embodiment. Inaddition, a reflective metal film 109 is formed on a second surface ofthe first substrate 100 b on which a cut pattern region 104 is formed.

Sidewalls of a light-emitting structure 110 may not be inclined as shownin FIG. 8A or may be inclined as shown in FIG. 8B. A method offabricating the light-emitting device 3 according to the third exemplaryembodiment will now be described as an example.

In the method of fabricating the light-emitting device 1 described abovewith reference to FIGS. 1 through 6, the substrate 100 a is attached tothe support substrate 160 after being separated into individualintermediate structures (i.e., chips). Then, the substrate 100 a is cutin the horizontal direction by using a laser beam.

In contrast, a substrate 100 a of the light-emitting device 3 accordingto the third exemplary embodiment is cut in the horizontal direction byusing a laser beam when in a wafer state (that is, before beingseparated into individual chips).

For example, the substrate 100 a of the light-emitting device 3according to the third exemplary embodiment is cut using a laser beambefore being attached to the support substrate 160. Here, the substrate100 a may be cut using a laser beam after or before an intermediatestructure is formed on a surface of the substrate 100 a.

Then, the reflective metal film 109 is formed on the second surface ofthe first substrate 100 b on which the cut pattern region 104 is formedand which remains after the substrate 100 a is cut. The reflective metalfilm 109 may be made of a material having high reflexibility, such assilver or aluminum.

Next, the first substrate 100 b is separated into individualintermediate structures (that is, chips).

The first substrate 100 b having the intermediate structure formedthereon is attached to the support substrate 160 in a lateral chipmanner (that is, such that the second surface of the substrate 100 bfaces the support substrate 160). Then, a first electrode 140 isconnected to a first conductive region 161 by a wire 145, and a secondelectrode 150 is connected to a second conductive region 162 by a wire155.

The operation of the light-emitting device 3 according to the thirdexemplary embodiment will now be described with reference to FIG. 9.

Referring to FIG. 9, light L3 generated within the light-emittingstructure 110 may exit the light-emitting structure 110 in a directiontoward the second electrode 150 without being reflected. In addition,light L4 generated within the light-emitting structure 110 may bereflected by the reflective metal film 109 and then exit thelight-emitting structure 110 in a direction toward the sidewalls of thelight-emitting structure 110 or in the direction toward the secondelectrode 150.

In the following drawings, the light-emitting device 1 according to thefirst exemplary embodiment is shown for ease of description. However, itis apparent to those of ordinary skill in the art that the followingdescription is also applicable to the light-emitting device 2 or 3according to the second or third exemplary embodiments.

FIG. 10 is a view showing a light-emitting apparatus 4 according to afourth exemplary embodiment of the present inventive concept.

Referring to FIG. 10, the light-emitting apparatus 4 according to thefourth exemplary embodiment includes a circuit board 300 and thelight-emitting device 1 disposed on the circuit board 300. Here, thesupport substrate 160 of the light-emitting device 1 is a submount.

The circuit board 300 includes a third conductive region 301 and afourth conductive region 302 which are electrically insulated from eachother. The third conductive region 301 and the fourth conductive region302 are disposed on a surface of the circuit board 300.

The first electrode 140 of the light-emitting device 1 may be connectedto the first conductive region 161 of the support substrate 160 by theconductive solder 171, and the first conductive region 161 may beconnected to the third conductive region 301 by a wire 331. The secondelectrode 150 of the light-emitting device 1 may be connected to thesecond conductive region 162 of the support substrate 160 by theconductive solder 172, and the second conductive region 162 may beconnected to the fourth conductive region 302 by a wire 332. However, itis obvious that those of ordinary skill in the art to which the presentinventive concept pertains can connect the above components in differentways from the way shown in FIG. 10.

FIG. 11 is a view showing a light-emitting apparatus 5 according to afifth exemplary embodiment of the present inventive concept. Referringto FIG. 11, the light-emitting apparatus 5 according to the fifthexemplary embodiment is different from the light-emitting apparatus 4according to the fourth exemplary embodiment in that a circuit board 300includes first and second through vias 303 and 304.

Specifically, a third conductive region 301 and a fourth conductiveregion 302, which are electrically insulated from each other, are formedon a surface of the circuit board 300, and a fifth conductive region 305and a sixth conductive region 306, which are electrically insulated fromeach other, are formed on the other surface of the circuit board 300.The third conductive region 301 is connected to the fifth conductiveregion 305 by the first through vias 303, and the fourth conductiveregion 302 is connected to the sixth conductive region 306 by the secondthrough vias 304.

FIG. 12 is a view showing a light-emitting apparatus 6 according to asixth exemplary embodiment of the present inventive concept. Referringto FIG. 12, the light-emitting apparatus 6 according to the sixthexemplary embodiment is different from the light-emitting apparatus 4according to the fourth exemplary embodiment in that it includes aphosphor layer 340 which surrounds the light-emitting device 1 andsecond transparent resin 350 which surrounds the phosphor layer 340.

The phosphor layer 340 may be a mixture of first transparent resin 342and phosphors 344. The phosphors 344 dispersed within the phosphor layer340 absorb light emitted from the light-emitting device 1 and convertthe wavelength of the light into another wavelength. Thus, when thephosphors 344 are dispersed more evenly, the light-emitting propertiesof the light-emitting apparatus 6 can be improved. In addition, when thephosphors 344 are dispersed more evenly, the wavelength conversion andcolor-mixing effect of the phosphors 344 can be enhanced. As shown inthe drawing, the phosphor layer 340 may be formed higher than the wires331 and 332 in order to protect the wires 331 and 332.

For example, the light-emitting apparatus 6 may include the phosphorlayer 340 in order to produce a white color. When the light-emittingdevice 1 emits light having a blue wavelength, the phosphors 344 mayinclude yellow phosphors. The phosphors 344 may also include redphosphors in order to increase a color-rendering index (CRI). When thelight-emitting device 1 emits light having an ultraviolet (UV)wavelength, the phosphors 344 may include all of red, green and bluephosphors.

The first transparent resin 342 may be any material that can dispersethe phosphors 344 in a stable manner. For example, the first transparentresin 342 may be epoxy resin, silicon resin, hard silicon resin,denatured silicon resin, urethane resin, oxetane resin, acrylic resin,polycarbonate resin, or polyimide resin.

The phosphors 344 may be any material that can absorb light from thelight-emitting structure 110 and convert the wavelength of the absorbedlight. For example, the phosphors 344 may be at least one ofnitride-based or oxynitride-based phosphors activated mainly by alanthanoid element such as europium (Eu) or cerium (Ce); alkaline earthhalogen apatite phosphors activated mainly by a lanthanoid element suchas Eu or a transition metal element such as manganese (Mn); alkalineearth metal halogen borate phosphors; alkaline earth metal aluminatephosphors; alkaline earth silicate phosphors; alkaline earth sulfidephosphors; alkaline earth thiogallate phosphors; alkaline earth siliconnitride phosphors; germanate phosphors; rare earth aluminate phosphorsactivated mainly by a lanthanoid element such as Ce; rare earth silicatephosphors; and organic or organic complex phosphors activated mainly bya lanthanoid element such as Eu. Specifically, phosphors listed belowmay be used. However, the phosphors 344 are not limited to the followingphosphors.

Examples of nitride-based phosphors activated mainly by a lanthanoidelement such as Eu or Ce include M₂Si₅N₈:Eu (M is at least one of Sr,Ca, Ba, Mg and Zn), MSi₇N₁₀:Eu, M_(1.8)Si₅O_(0.2)N₈:Eu, andM_(0.9)Si₇O_(0.1)N₁₀:Eu (M is at least one of Sr, Ca, Ba, Mg and Zn).

Examples of oxynitride-based phosphors activated mainly by a lanthanoidelement such as Eu or Ce include MSi₂O₂N₂:Eu (M is at least one of Sr,Ca, Ba, Mg and Zn).

Examples of alkaline earth halogen apatite phosphors activated mainly bya lanthanoid element such as Eu or a transition metal element such as Mninclude M₅(PO₄)₃X:R (M is at least one of Sr, Ca, Ba, Mg and Zn, X is atleast one of F, Cl, Br and I, and R is at least one of Eu, Mn and Eu).

Examples of alkaline earth metal halogen borate phosphors includeM₂B₅O₉X:R (M is at least one of Sr, Ca, Ba, Mg and Zn, X is at least oneof F, Cl, Br and I, and R is at least one of Eu, Mn and Eu).

Examples of alkaline earth metal aluminate phosphors include SrAl₂O₄:R,Sr₄Al₁₄O₂₅:R, CaAl₂O₄:R, BaMg₂Al₁₆O₂₇:R, BaMg₂Al₁₆O₁₂:R, andBaMgAl₁₀O₁₇:R(R is at least one of Eu, Mn and Eu).

Examples of alkaline earth sulfide phosphors include La₂O₂S:Eu,Y₂O₂S:Eu, and Gd₂O₂S:Eu.

Examples of rare earth aluminate phosphors activated mainly by alanthanoid element such as Ce include YAG phosphors represented bycompositional formulas such as Y₃Al₅O₁₂:Ce, (Y_(0.8)Gd_(0.2))₃Al₅O₁₂:Ce,Y₃(Al_(0.8)Ga_(0.2))₅O₁₂:Ce, and (Y, Gd)₃(Al, Ga)₅O₁₂. Other examplesinclude phosphors such as Tb₃Al₅O₁₂:Ce and Lu₃Al₅O₁₂:Ce in which part orall of Y has been replaced by Tb, Lu, or the like.

Alkaline earth silicate phosphors contain silicate, and major examplesof the alkaline earth silicate phosphors include (SrBa)₂SiO₄:Eu.

Examples of other phosphors include ZnS:Eu, Zn₂GeO₄:Mn, and MGa₂S₄:Eu (Mis at least one of Sr, Ca, Ba, Mg and Zn, and X is at least one of F,Cl, Br, and I).

The above phosphors may also include at least one of Tb, Cu, Ag, Au, Cr,Nd, Dy, Co, Ni and Ti, instead of or in addition to Eu. Furthermore,other phosphors that offer similar performance and effects to those ofthe phosphors listed above can also be used.

The second transparent resin 350 is lens-shaped and diffuses lightemitted from the light-emitting device 1. The curvature and flatness ofthe second transparent resin 350 may be adjusted to control the lightdiffusion/extraction properties. The second transparent resin 350surrounds the phosphor layer 340 to protect the phosphor layer 340. Thatis, the second transparent resin 350 surrounds the phosphor layer 340because the properties of the phosphor layer 340 may deteriorate whencontacting, for example, moisture.

The second transparent resin 350 may be any material through which lightcan pass. For example, the second transparent resin 350 may be epoxyresin, silicon resin, hard silicon resin, denatured silicon resin,urethane resin, oxetane resin, acrylic resin, polycarbonate resin, orpolyimide resin.

FIG. 13 is a view showing a light-emitting apparatus 7 according to aseventh exemplary embodiment of the present inventive concept. Referringto FIG. 13, phosphors 344 are formed along the profiles of thelight-emitting device 1 and a circuit board 300. Here, the phosphors 344may be coated on the light-emitting device 1 and the circuit board 300without requiring first transparent resin (indicated by referencenumeral 342 in FIG. 12).

When the phosphors 344 are coated on the light-emitting device 1 and thecircuit board 300 without requiring the first transparent resin, amonolayer 350 of transparent resin may surround the light-emittingdevice 1.

FIG. 14 is a view showing a light-emitting apparatus 8 according to aneighth exemplary embodiment of the present inventive concept. Referringto FIG. 14, the light-emitting apparatus 8 according to the eighthexemplary embodiment is different from the light-emitting apparatus 4according to the fourth exemplary embodiment in that it includes firsttransparent resin 342 which surrounds the light-emitting device 1,phosphors 344 which are formed on the first transparent resin 342, andsecond transparent resin 350 which is formed on the phosphors 344. Thatis, since the first transparent resin 342 and the phosphors 344 arecoated separately without being mixed with each other, the phosphors 344may be formed thinly and conformally along a surface of the firsttransparent resin 342.

FIG. 15 is a view showing a light-emitting apparatus 9 according to aninth exemplary embodiment of the present inventive concept. Thelight-emitting apparatus 9 according to the ninth exemplary embodimentis a topview-type light-emitting package. However, the present inventiveconcept is not limited thereto.

Referring to FIG. 15, the support substrate 160 on which thelight-emitting device 1 is mounted is disposed on a package body 210.Specifically, a slot 212 is formed in the package body 210, and thesupport substrate 160 having the light-emitting device 1 mounted thereonis disposed in the slot 212. The slot 212 may have inclined sidewalls.Thus, light emitted from the light-emitting device 1 may be reflected bythe sidewalls and then proceed forward. The size of the slot 212 may bedetermined in view of the degree to which light generated by thelight-emitting device 1 is reflected by the sidewalls of the slot 212,the angle at which the light is reflected by the sidewalls of the slot212, the type of transparent resin that fills the slots 212, the type ofphosphors, and the like. The support substrate 160 may be placed in thecenter of the slot 212 since chromatic non-uniformity can be easilyprevented when the light-emitting device 1 is equidistant from thesidewalls of the slot 212.

The package body 210 may be made of an excellently lightfast organicmaterial, such as silicon resin, epoxy resin, acrylic resin, urea resin,fluorine resin or imide resin, or may be made of an excellentlylightfast inorganic material such as glass or silica gel. In addition,thermosetting resin may be used in order to prevent heat from meltingpackage body 210 while the light-emitting apparatus 9 is fabricated.Various fillers, such as aluminum nitride, aluminum oxide and compoundsof the same, may also be added to resin in order to relieve thermalstress of the resin. The package body 210 may also be made of a materialother than resin. For example, part (e.g., the sidewalls) or all of thepackage body 210 may be made of a metal material or a ceramic material.When all of the package body 210 is made of a metal material, heatgenerated by the light-emitting device 1 can be easily dissipated out ofthe package body 210.

Leads 214 a and 214 b are formed in the package body 210 and areelectrically connected to the light-emitting device 1. Thelight-emitting device 1 may be electrically connected to the supportsubstrate 160, and the support substrate 160 may be connected to theleads 214 a and 214 b by vias. The leads 214 a and 214 b may be made ofa highly thermally conductive material since heat generated by thelight-emitting device 1 can be dissipated directly out of the packagebody 210 through the leads 214 and 214 b when the leads 214 a and 214 bare made of a highly thermally conductive material.

Although not shown in the drawing, at least part of the slot 212 may befilled with a transparent resin layer. In addition, phosphors may beformed on the transparent resin layer. Alternatively, the phosphors maybe mixed with the transparent resin layer.

FIGS. 16 through 18 are views showing a light-emitting apparatus 10according to a tenth exemplary embodiment of the present inventiveconcept. Specifically, FIGS. 16 through 18 are views showing an array ofthe light-emitting devices 1 disposed on a circuit board 300. Inparticular, FIGS. 17 and 18 show phosphor layers 340 and secondtransparent resin 350 which are formed on the array of thelight-emitting devices 1.

Referring to FIG. 16, third conductive regions 301 and fourth conductiveregions 302 are formed on the circuit board 300 and extend in onedirection to be parallel to each other. The light-emitting devices 1 arearranged in a line in the direction in which the third and fourthconductive regions 301 and 302 extend. As described above, the firstelectrode 140 of each of the light-emitting devices 1 may be connectedto a corresponding one of the third conductive regions 301 by thesupport substrate 160 and a wire 331, and the second electrode 150 ofeach of the light-emitting device 1 may be connected to a correspondingone of the fourth conductive regions 302 by the support substrate 160and a wire 332.

When appropriate biases are applied to the third and fourth conductiveregions 301 and 302, the light-emitting structure 110 (see FIG. 1) ofeach of the light-emitting devices 1 may be forward-biased. Accordingly,the light-emitting devices 1 may emit light.

Referring to FIG. 17, the phosphor layers 340 and the second transparentresin 350 may be formed in a linear manner. For example, when thelight-emitting devices 1 are arranged along the direction in which thethird and fourth conductive regions 301 and 302 extend, the phosphorlayers 340 and the second transparent resin 350 may also be arrangedalong the direction in which the third and fourth conductive regions 301and 302 extend. In addition, the phosphors 340 and the secondtransparent resin 350 may completely surround the third and fourthconductive regions 301 and 302.

Referring to FIG. 18, the phosphor layers 340 and the second transparentresin 350 may be formed in a dotted manner. In this case, each of thephosphor layers 340 and each of the second transparent resin 350 maysurround a corresponding one of the light-emitting devices 1.

FIG. 19 is a view showing a light-emitting apparatus according to aneleventh exemplary embodiment of the present inventive concept. Thelight-emitting apparatus of FIG. 19 can be applied to variousapparatuses such as lighting apparatuses, display apparatuses, andmobile apparatuses (mobile phones, MP3 players, navigations, etc.). Thelight-emitting apparatus shown in FIG. 19 is an edge-type backlight unit(BLU) used in a liquid crystal display (LCD). Since LCDs are notself-luminous, they use a BLU as their light source. Generally, a BLU isdisposed behind a liquid crystal panel and provides light to the liquidcrystal panel.

Referring to FIG. 19, the BLU includes the light-emitting device 1, alight guide plate 410, a reflective plate 412, a diffusion sheet 414,and a pair of prism sheets 416. The light-emitting device 1 provideslight and may be of a side-view type.

The light guide plate 410 guides light toward a liquid crystal panel450. The light guide plate 410 is a panel made of a transparent plasticmaterial such as acryl and guides light emitted from the light-emittingdevice 1 toward the liquid crystal panel 450 which is disposed above thelight guide plate 410. Various patterns 412 a are printed at the back ofthe light guide plate 410 to guide light, which is input to the lightguide plate 410, toward the liquid crystal panel 450.

The reflective plate 412 is disposed on a lower surface of the lightguide plate 410 and thus reflects light, which is emitted downward fromthe light guide plate 410, upward. That is, the reflective plate 412reflects light, which has not been reflected by the various patterns 412a printed at the back of the light guide plate 410, toward an outputsurface of the light guide plate 410. In so doing, the reflective plate412 reduces light loss and improves the uniformity of light which isoutput from the output surface of the light guide plate 410.

The diffusion sheet 414 diffuses light output from the light guide plate410, thereby preventing the light from being concentrated in a specificarea.

Each of the prism sheets 416 has a predetermined array of triangularprisms on an upper surface thereof. The prism sheets 416 typicallyconsist of two sheets, and an array of triangular prisms formed on oneof the two prism sheets 416 cross an array of triangular prisms formedon the other one of the two prism sheets 416 at a predetermined angle,so that light diffused by the diffusion sheet 414 can proceed in adirection perpendicular to the liquid crystal panel 450.

FIGS. 20 through 23 are views showing light-emitting apparatusesaccording to twelfth through fifteenth exemplary embodiments of thepresent inventive concept. The light-emitting apparatuses shown in FIGS.20 through 23 are exemplary end products to which the light-emittingdevice 1 described above can been applied. Specifically, FIG. 20 shows aprojector, FIG. 21 shows a headlight of a vehicle, FIG. 22 shows astreetlight, and FIG. 23 shows a lamp. The light-emitting device 1 usedin the light-emitting apparatuses of FIGS. 20 through 23 may be of atop-view type.

Referring to FIG. 20, light emitted from a light source 410 passesthrough a condensing lens 420, a color filter 430, and a shaping lens440. Then, the light is reflected by a digital micro-mirror device 450and passes through a projection lens 480 to reach a screen 490. Alight-emitting device according to the present inventive concept isincluded in the light source 410.

While the present inventive concept has been particularly shown anddescribed with reference to exemplary embodiments thereof, it will beunderstood by those of ordinary skill in the art that various changes inform and detail may be made therein without departing from the spiritand scope of the present inventive concept as defined by the followingclaims. The exemplary embodiments should be considered in a descriptivesense only and not for purposes of limitation.

1. A method of fabricating a light-emitting apparatus, the methodcomprising: preparing a monocrystalline substrate; forming anintermediate structure on the substrate, the intermediate structurecomprising a light-emitting structure which comprises a first conductivepattern of a first conductivity type, a light-emitting pattern, and asecond conductive pattern of a second conductivity type stackedsequentially, a first electrode which is electrically connected to thefirst conductive pattern, and a second electrode which is electricallyconnected to the second conductive pattern, wherein the first electrodeand the second electrode include at least one of W, Pt and titanium(Ti), and the second electrode of the light-emitting device is connectedto a first conductive region of a support substrate by a conductivesolder; forming a polycrystalline region, which extends in a horizontaldirection, by irradiating a laser beam to the substrate in thehorizontal direction; and cutting the substrate in the horizontaldirection along the polycrystalline region.
 2. The method of claim 1,further comprising bonding the substrate having the intermediatestructure formed thereon to a support substrate between the forming ofthe intermediate structure and the forming of the polycrystallineregion.
 3. The method of claim 2, wherein the first conductive patternis wider than the second conductive pattern such that the firstconductive pattern has a protruding region, the first electrode isformed on the protruding region of the first conductive pattern, thesecond electrode is formed on the second conductive pattern, and thesubstrate having the intermediate structure formed thereon is bonded tothe support substrate such that the first and second electrodes face thesupport substrate.
 4. The method of claim 1, wherein sidewalls of thelight-emitting structure are inclined, and the second electrode isformed on a top surface and the sidewalls of the light-emittingstructure.
 5. The method of claim 1, wherein when the substrate is cutin the horizontal direction, the substrate is divided into a firstsubstrate and a second substrate from the polycrystalline region,wherein the intermediate structure is formed on a first surface of oneof the first and second substrates, and a cut pattern region is formedon a second surface of one of the first and second substrates, whereinat least part of the cut pattern region is polycrystalline.
 6. A methodof fabricating a light-emitting apparatus, the method comprising:preparing a monocrystalline substrate; forming an intermediate structureon the substrate, the intermediate structure comprising a light-emittingstructure which comprises a first conductive pattern of a firstconductivity type, a light-emitting pattern, and a second conductivepattern of a second conductivity type stacked sequentially, an electrodeelectrically connected to the second conductive pattern, wherein theelectrode includes at least one of W, Pt and titanium (Ti), and theelectrode of the intermediate structure is connected to a firstconductive region of a support substrate by a conductive solder; forminga region, whose material quality is different from that of the otherregions of the substrate and which extends in a horizontal direction, byirradiating a laser beam to the substrate in the horizontal direction;and cutting the substrate in the horizontal direction along the region.7. The method of claim 6, further comprising the substrate is made ofsapphire (Al203), silicon carbide (SiC), or gallium nitride (GaN). 8.The method of claim 6, further comprising the light-emitting patternincludes A1GaN or InGaN.
 9. The method of claim 6, further comprisingthe light-emitting pattern have a multiple quantum well (MQW) structure.10. The method of claim 6, wherein the first conductivity type is ann-type and the second conductivity type is a p-type.
 11. The method ofclaim 6, further comprising an ohmic layer is formed between thelight-emitting structure and the electrode.
 12. The method of claim 11,wherein the ohmic layer includes at least one of indium tin oxide (ITO),zinc (Zn), zinc oxide (ZnO), silver (Ag), tin (Ti), aluminum (Al), aurum(Au), nickel (Ni), indium oxide (In2O3), tin oxide (SnO2), copper (Cu),tungsten (W), and platinum (Pt).
 13. The method of claim 6, furthercomprising a buffer layer is formed between the substrate and the firstconductive pattern.
 14. The method of claim 13, wherein the buffer layeris made of InAlGaN or SiCN.
 15. The method of claim 6, furthercomprising the first conductive region is connected to a secondconductive region by a wire.